ADHESION PROPERTIES OF A STRUCTURAL ETCH-STOP MATERIAL FOR USE IN MULTILAYER ELECTRONIC WIRING STRUCTURES

A thermally stable copolymer of a polyimide and a dianiline terminated polydimethylsiloxane has been developed for use as a structural oxyge n etch barrier material in high performance multilayer electronic wiri ng structures. We report on the preparation of the etch barrier materi al and on investigations of the etch stop and adhesion properties of t his material. Studies on the effects of adhesion-promoting plasma trea tments are supported by x-ray photoelectron spectroscopy (XPS) and Rut herford backscattering spectrometry (RES) data. Before plasma treatmen t, it is observed that the siloxane component segregates to the surfac e. After either an O-2 reactive ion etch treatment or H2O plasma expos ure, the unusual XPS charging effects are interpreted as a surface lay er containing two distinct phases: the etched polyimide fraction and a partial overlayer of a carbon containing SiO2.